NATURAL IllSTOftY-. 
351 
which it is incapable of contracting, bends its body into the 
form of a bow, and then shoots forward front the tail ; but 
it is very different with the worm, which has a power of con- 
tracting or lengthening itself at will. There is a spiral 
muscle, that runs round its whole body, from the head to 
the tail, somewhat resembling a wire wound round a walk- 
ing-cane, which, when slipped off, and one end extended 
anil held fast, will bring the other nearer to it; in this man- 
ner the earth-worm, having shot out or extended its body, 
takes hold by the slime of the fore part of its body, and so 
contracts and brings forward the hinder part ; in this manner 
it moves onward, not without great effort; but the occa- 
sions for its progressive motion are few. 
As it is designed for living under the earth, and leading a 
life of obscurity, so it seems tolerably adapted to its situa- 
tion. Its body is armed with small stiff sharp burs or prickles, 
w hich it can erect or depress at pleasure ; under the skin there 
lies a slimy juice, to be ejected as occasion requires at cer- 
tain perforations, between the rings of the muscles, to lubri- 
cate its body, and facilitate its passage into the earth. Like 
most other insects, it has breathing holes along the back, 
adjoining each ring; but it is without bones, without eyes, 
without ears, and, properly, without feet. It has a mouth, 
and also an alimentary canal, which runs along to the very 
point of the tail. In some worms, however, particularly such 
as are found in the bodies of animals, this canal opens 
towards the middle of the belly, at some distance from the 
tail. The intestines of the earth-worm are always found 
filled with a very fine earth, which seems to be the only 
nourishment these animals are capable of receiving. 
The animal is entirely without brain, but near the head : s 
placed the heart, which is seen to beat with a very distinct 
motion, and round it are the spermatic vessels, forming a 
number of little globules, containing a milky fluid, which 
have an opening into the belly, not far from the head: they 
are also often found to contain a number of eggs, which are 
laid in the earth, and are hatched in twelve or fourteen days 
into life, by the genial warmth of their situation. 
When the eggs are laid in the earth, which, in about 
fourteen days, as has been said, are hatched into maturity, 
the young ones come forth very small, but perfectly formed, 
and suffer no change during their existence : but how long 
their life continues is not well known, but it certainly holds 
tor more than two or three seasons. Daring the winter, they 
bury themselves deeper in the earth, and seem, in some mea- 
sure, to share the general torpidity of the insect tribe. In 
